Process of manufacturing n-mercaptomethylphthalimide

ABSTRACT

A process of manufacturing N-mercaptomethylphthalimide is described herein. The process involves first forming a solution of sodium bisulfide in situ by reacting a sodium compound with hydrogen sulfide in the presence of a solvent. Then, a solution is formed consisting of N-halomethylphthalimide and tetrahydrofuran which is reacted with the sodium bisulfide solution to form N-mercaptomethylphthalimide.

finite States Patent [191 Kalbfeld Aug. 28, 1973 PROCESS OF MANUFACTURING 778.

N-MERCAPTOMETHYLPHTHALIMIDE [76] Inventor: Jules Kalbfeld, 2751 Wright Ave., primary Examiner joseph Narcavage pmole' 94564 Attorney-Daniel C. Block et al. [22] Filed: Aug. 12, 1971 [21] Appl. No.: 171,375

[57] ABSTRACT Related US. Application Data Continuation-impart 0f NO. A process of manufacturing N-mercaptomethylphthali- 1969, abandoned. mide is described herein. The process involves first forming a solution of sodium bisulfide in situ by react- [52] US. Cl 260/326 S, 424/274 i a Sodium compound with hydrogen lfid in the [51 1 C07! 27/52 presence of a solvent. Then, a solution is formed con- [58] Field of Search 260/326 S Sisting of N halomethylphthalimide and tetrahydro furan which is reacted with the sodium bisulfide solu- [56] References Cited OTHER PUBLICATIONS Wagner et al. Synthetic Organic Chemistry (1953) p.

tion to form N-mercaptomethylphthalimide.

4 Claims, No Drawings PROCESS OF MANUFACTURING N-MERCAPTOMETI-IYLPHTHALIMIDE CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of copending application Ser. No. 868,627, filed Oct. 22, 1969, and now abandoned, entitled PROCESS OF MANU- FACTURING N-MERCAPTOMETHYLPHTHALL MIDE.

BACKGROUND OF THE INVENTION In the art of manufacturing N-mercaptoalkylphthalimides having at least two or more carbon atoms, it is the usual practice to react the respective phthalimide alkyl halide with potassium hydrosulfide. The reaction is usually carried out at elevated temperatures in an alcohol solvent. High yields of the end product are reported. A more detailed study of this procedure can be found in textbooks by Beilstein and Wagner et al.

When this procedure is employed to manufacture the methyl derivative of the N-mercaptoalkylphthalimide, the end product cannot be readily identified. The reaction between the components form an agglomeration of unusable compounds. No theory or hypothesis can be advanced for the failure of this process to manufacture the desired end product.

BRIEF DESCRIPTION OF THE INVENTION It has been discovered that N-mercaptomethylphthalimide can be manufactured in reasonable yields by forming sodium bisulfide in situ by reacting sodium methylate with hydrogen sulfide in an alcohol solvent or in the alternative forming the sodium bisulfide by reacting a sodium dispersion with hydrogen sulfide. Thereafter, N-halomethylphthalimide in tetrahydrofuran solvent is reacted with the sodium bisulfide at elevated temperatures.

DETAILED DESCRIPTION OF THE INVENTION In the practice of the present invention, sodium bisulfide is first manufactured in situ by either reacting sodium methylate with hydrogen sulfide or reacting a sodium dispersion with hydrogen sulfide to fonn the sodium bisulfide. The reaction of the sodium methylate with hydrogen sulfide is carried out in the presence of an alcohol solvent such as methanol, ethanol, or isopropanol. Then, a solution is fonned by dissolving N- halomethylphthalimide in tetrahydrofuran and adding to the sodium bisulfidesolution. It is essential to the practice of the present invention to dissolve the N- halomethylphthalimide in tetrahydrofuran because other solvent systems will not produce the desired end product. The reaction components are then heated up to about 60C. for a sufficient length of time to form the end product. The time necessary to form the end product is usually indicated by the cessation of the evolution of hydrogen sulfide. The reaction mixture should be kept under inert atmosphere to prevent formation of diphthalimidomethyl disulfide. The reaction product is filtered and the filtrate stripped to a residue which can be recrystallized from methylene chloride. The halo moiety of the N-halomethylphthalimide can be selected from the group consisting of chlorine or bromine and mixtures thereof.

The compositions manufactured by the process of the present invention are highly reactive intermediates to form pesticides. Thus, the N-mercaptomethylphphosphorodithioic thalimide can be further reacted with phosphorus derivatives and an aldehyde to form insecticides, miticides and parasiticides having the following formula:

EXAMPLE I An excess of hydrogen sulfide was reacted with 684 grams of 25 percent sodium methylate in a methanol solvent to give a solution of sodium hydrogen sulfide.

. A solution of N-chloromethylphthalimide in tetrahydrofuran was prepared by adding 586.5 grams of chloromethylphthalimide to 2,500 milliliters of tetrahydrofuran. The N-chloromethylphthalimide solution was added to the sodium hydrogen sulfide solution. The components were heated to 45C. until no further hydrogen sulfide was given off. The reaction product was filtered, stripped and recrystallized with methylene chloride. The yield was 62 percent.

EXAMPLE II A sodium dispersion, 3.56 ml., containing 23 mg. of sodium in 0.173 milliliters was charged to a 5 milliliter reactor and washed in with 10 milliliters of tetrahydrofuran that were dried over a molecular sieve after being distilled over sodium hydroxide pellets. Hydrogen sulfide was pressed over the surface until a white precipitate resulted and no more hydrogen evolved. A solution of 1,955 milligrams of N-chloromethylphthalimide in 15 millimeters of tetrahydrofuran was prepared and added to the mixture of tetrahydrofuran and sodium dispersion. A warm-water bath was brought in contact with the reactor. The reactor was kept warm until no further hydrogen sulfide was observed. The mixture was stripped of tetrahydrofuran, the residue taken up in diethyl ether and allowed to stand overnight. The reaction product was stripped and identified as N-mercaptomethylphthalimide in an amount of 42.5 percent yield.

ml. of 25 percent sodium methylate in a methanol solvent to get a solution of sodium hydrogen sulfide. Using the methanol as a solvent, 1,955 mg. of chloromethylphthalimide were added as solids to this solution.

. No identifiable product could be found from this reaction.

EXAMPLE IV chloromethylphthalimide were added as solids. No reaction took place.

EXAMPLE V The process as outlined in Example 111 was repeated in its entirety except the N-chloromethylphthalimide was dissolved in tetrahydrofuran at 1.5 mls. per mg. and allowed to react over the weekend. The melting point of the crude product was 126-136. The product was filtered and stripped to a residue to provide 65 percent yield of the desired product.

EXAMPLE VI A sodium dispersion, 0.865 mls. was charged to a 50 ml. reactor. The precipitate was washed in with 5 ml. of toluene as a solvent. Hydrogen sulfide was passed over the surface until no more hydrogen was liberated from the mixture. Then, 0.977 g. of N- chloromethylphthalimide was charged to the mixture at -67C. The batch was allowed to warm to room temperature. The resultant product was filtered. No reaction took place and all the starting materials were recovered.

EXAMPLE VII Preparation of S-(Phthalimido-N-methylthiomethyl)- 0,0-diethylphosphorodithioate Twenty-seven and nine-tenths grams (0.15M) of diethylphosphorodithioic acid was cooled below C. and 15.1 cc. (0.2M) of formalin (37 percent) was added with stirring and cooling below 20C. The mixture was shaken with 100 cc. of benzene, the aqueous layer removed and the benzene layer dried over anhydrous magnesium sulfate, then filtered into a flask equipped with an apparatus for the continuous removal of water. To the flask was added 19.2 g. (0.1M) of N-mercaptomethylphthalimide, the stirrer was started and the mixture refluxed for 3.5 hours. During this time 1.2 cc. of water collectedin 'the separator. After cooling, the mixture was made slightly basic with cold dilute sodium bicarbonate solution, the aqueous phase removed and the benzene layer washed with dilute sodium chloride solution, dried over anhydrous magnesiumsulfate, filtered and evaporated to give 31.7 g. (81 percent of theory) of the product was a viscous liquid,

Analysis C H N '58 Theory 43.0 4.61 3.58 24.6 Found 44.6 4.82 3.71 25.0

As can be seen from the above examples, it is essen- 'tial to the practice of the present invention that tetrahydrofuran be employed as a solvent for the N- halomethylphthalimide.

The following is a list of compounds prepared according to the aforedescribed procedures. Compound numbers have been assigned to each compound and are used throughout the balance of the application.

Compound No. R R n '1 OCJ-l, OCJI, 1.5928 2 OCH, OCH, 1 .5968 3 CH, OCH, 1.6088 4 QB, OC,H i 1.5793

No. 1 prepared in Example 111.

As previously mentioned, the herein described composition produced in the above-described manner are biologically active compounds which are useful and valuable in controlling various pest organisms. The compounds of this invention were tested as miticides in the following manner.

Miticide evaluation test The two-spotted mite Tetranychus telarius (Linn) was employed in tests for miticidal activity. Young pinto bean plants in the primary leaf stage were used as host plants. The young pinto bean plants were infested with several hundred mites. Dispersions of candidate materials were prepared by dissolving 0.1 grams in 10 ml. of a suitable solvent, usually acetone. Aliquots of the toxicant solutions were suspended in water containing 0.0175 percent v./v. Sponto 221 which is described as a polyoxy-ethylene sorbitan monolaurate ether of alkylated phenols blended with organic sulfonates, emulsifying agent, the amount of water being sufficient to give concentrations of active ingredient ranging from 0.25 percent to 0.005 percent. The test suspensions were then sprayed on the infested pinto bean plants. After seven days, mortalities of post-embryonic and ovicidal forms were determined. The percentage of kill was determined by comparison with control plants which had not been sprayed with the candidate compounds The LD-SO value was calculated using wellknown procedures. The LD-50 values are reported under the columns PE and Eggs" in the table below.

Systemic evaluation test tration never exceeds about 1 percent. The toxicants were initially tested at a concentration of 10 parts per million (ppm). Immediately after the plants were placed in the test solutions they were infested with mites. Mortalities were determined after seven days. The percentage of kill was determined by comparison with control plants which had been placed in distilled water only. The LD-SO value was calculated using wellknown procedures. The LD-50 values in ppm. are reported under the column Systemic in Table l.

The compounds were also found to be active against black bean aphid (Aphis fabae (Scop.)). The same test procedure as given for the two-spotted mite above was used for black bean aphid except that nasturtium (Tropaeolurn sp.) plants approximately 2 to 3 inches tall were used as the host plant.

TABLE I Table ll Two-Spotted Mites Efi'icacy LD-SO Dosage PE 8 ss Compound No. (P.P.M,) So. At

Systemic 5 l 65 75 l00 Compound No. Percent Concentration (RPM) 2 25 33 100 i 0.003 0.00] 0.005 8 3 30 I00 90 2 0.0008 0.005 0.03 4 4 65 80 80 3 0.003 0.005 0.03 4 4 0.003 0.003 0.03 l0 What is claimed is:

l0 1. A process of forming N-mercaptomethylphthali- Internal animal parasite systemic tests mide comprising the steps The following procedure describes the chemotheraa. Forming a sodium bisulfide solution in situ by repeutic efficacy tests utilized to demonstrate the animal acting a sodium compound selected from a sodium parasitology activity of the compositions of the present dispersion, sodium methylate and mixtures thereof invention. with hydrogen sulfide, said sodium compound Unparasitized weanling mice were offered medicated being mixed with an alcohol solvent; food for 1-2 days prior to inducing infections, and for b, Forming a solution of tetrahydrofuran and N- a total of 21 days infections were administered per os halomethylphthalimide selected from the group using 100-300 embryonated Ova/mouse 0f yp consisting of N-chloromethylphthalimide, N velafa and 100-300 embryonated Ova/mouse of bromomethylphthalimide, and mixtures thereof; Asplculuris telmptem 0 0. Reacting the solutions formed in steps (a) and (b) A suitable number of unmedicated littermate mice together at a temperature f up to about 60C to also received the above infection and served as control f NmercaPtomeMlPhthalimide to determine the comparative efficacy of the medica- The process f claim 1 wherein the sodium tions. All mice were sacrificed after 21 days (the medi- 25 cation period) and the residual parasites found in the intestine were identified and counted. These counts in the medicated groups were compared to the unmedicated (controls) and a percent efficacy was assigned, (M/lCXl00)-l00 efficacy.

pound is sodium methylate.

3. The process of claim 1 wherein the sodium compound is a sodium dispersion.

4. The process of claim 1 wherein the N- halomethylphthalimide is N-chloromethylphthalimide.

5. g V UNITED STATES PATENT OFFICE CERTIFICATE OF COREECTION- atent No, 3,755,355, Datgd August 28, 1973 fl Y Jules Kalbfeld.

It is certified that error appears in the above-identified patentnd that said Letters Patent are hereby corrected as shown below:

On Page l, in the patent heading, the phrase ..-assignor to Stauffer Chemical Companv. w r Y :orporation of Delaiware should be inserteJd In- Column 1, paragraph 1, the portion reading "and now abandoned, entitled- PROCESS OF MANUFACTURING NMERCAPTO METHYLPHTHAL'IMIDE. should.read ---entitled PROCESS OF MANU- FACTURING N-MERCAPTOMETHYLPHTHALIMIDE, and now abandoned.---

In Column 2, line 43, the word "pressed" should read --=--passed--.

In Column 3, line 18, the numerals "0.977" should read .977--- In -Colman 3, line 19, the word "was" should read ---were-'---.

In Column 3, line 46, the word "was" should read aS o' y In Column 4, line 34, the portion of the line reading "pounds The LD-SO" should read --pounds. The LD-50---.

in Column A, line 51, the portion of the line reading "diluting distilled water." should read --diluting with distilled water.----

In Colman 5, TABLE I, the heading "PE tg Eggs" should read ---PE 'Eggs-'-.

Signed and sealed this 24th day of September 1974. J

(SEAL) Attest:

MCCOY M. GIBSON JR. c. MARSHALL DANN Arresting Officer Commissioner of Patents 

2. The process of claim 1 wherein the sodium compound is sodium methylate.
 3. The process of claim 1 wherein the sodium compound is a sodium dispersion.
 4. The process of claim 1 wherein the N-halomethylphthalimide is N-chloromethylphthalimide. 